82801BA Datasheet, PDF (177/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

Functional Description
5.16.2.3
7. Wait for data to arrive (from USB). Write incoming bytes into memory beginning at TD
BufferPointer. Internal HC buffer should signal end of data packet. Number of bytes received
must be (TD Max-Length; The length of the memory area referenced by TD BufferPointer
must be (TD Max-Length. [Concurrent system memory and USB Accesses].
8. Issue handshake based on status of data received (Ack or Time-out). Go to 10.
9. Wait for handshake, if required [End of USB Transaction].
10. Update Status [PCI Access] (TD.Status and TD.ActualLength).
If the TD was an isochronous TD, mark the TD inactive. Go to 12.
If not an isochronous TD, and the TD completed successfully, mark the TD inactive. Go to 11.
If not successful, and the error count has not been reached, leave the TD active. If the error
count has been reached, mark the TD inactive. Go to 12.
11. Write the link pointer from the current TD into the element pointer field of the QH structure. If
the Vf bit is set in the TD link pointer, go to 2.
12. Proceed to next entry.
Command Register, Status Register, and TD Status Bit Interaction
Table 5-64. Command Register, Status Register and TD Status Bit Interaction
Condition
ICH2 USB Status Register Actions
CRC/Time Out Error Set USB Error Int bit¹, Clear HC Halted bit
Illegal PID, PID Error,
Max Length (illegal)
Clear Run/Stop bit in command register
Set HC Process Error and HC Halted bits
PCI Master/Target
Abort
Suspend Mode
Clear Run/Stop bit in command register
Set Host System Error and HC Halted bits
Clear Run/Stop bit in command register²
Set HC Halted bit
Resume Received and
Set Resume received bit
Suspend Mode = 1
Run/Stop = 0
Clear Run/Stop bit in command register
Set HC Halted bit
configuration Flag Set Set configuration Flag in command register
HC Reset/Global Reset
Clear Run/Stop and configuration Flag in
command register
Clear USB Int, USB Error Int, Resume received,
Host System Error, HC Process Error, and HC
Halted bits
IOC = 1 in TD Status Set USB Int bit
Stall
Set USB Error Int bit
Bit Stuff/Data Buffer
Error
Set USB Error Int bit¹
Short Packet Detect Set USB Int bit
TD Status Register Actions
Clear Active bit¹ and set Stall
bit¹
Clear Active bit¹ and set Stall bit
Clear Active bit¹ and set Stall
bit¹
Clear Active bit
NOTES:
1. Only If error counter counted down from 1 to 0
2. Suspend mode can be entered only when Run/Stop bit is 0
82801BA ICH2 and 82801BAM ICH2-M Datasheet
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